How to figure out your property tax: a step-by-step guide

Last updated 2026-07-09

What is the basic formula for calculating property tax?

The math is simple. Property tax equals assessed value multiplied by the tax rate. That's it.

Here's how those terms break down. Assessed value is the dollar figure your local assessor assigns to your property, usually expressed as a percentage of market value (sometimes 100%, sometimes less). Tax rate is the combined rate set by every taxing body that covers your address: the county, the municipality, the school district, any special districts. The combined rate is usually expressed in mills, where one mill equals $1 of tax per $1,000 of assessed value ^[1].

So if your home has an assessed value of $300,000 and your combined mill rate is 20 mills (2%), your annual property tax is $6,000. Knock off a $25,000 homestead exemption first if your state offers one, and the taxable value drops to $275,000, making the bill $5,500.

The formula written plainly: (Assessed Value minus Exemptions) x Tax Rate = Property Tax Due.

Each piece of that formula can be wrong, and each piece can be challenged. Most homeowners who successfully lower their bills find the error in the assessed value, not the rate, because rates are set publicly and applied the same way to everyone in the jurisdiction.

How do assessed value and market value differ?

Market value is what your home would sell for today between a willing buyer and a willing seller. Assessed value is the number your assessor uses for tax purposes, and it may or may not equal market value.

States handle this very differently. California's Proposition 13 caps assessed value increases at 2% per year regardless of market appreciation, so a home bought in 1995 might have an assessed value far below current market ^[2]. Texas assesses at 100% of market value but caps annual assessment increases at 10% for homesteaded properties ^[3]. New York City uses a fractional assessment ratio that varies by property class, so Class 1 residential properties are assessed at roughly 6% of market value ^[4].

The ratio of assessed value to market value is called the assessment ratio (or assessment level). The Lincoln Institute of Land Policy publishes annual data showing that effective residential assessment ratios range from under 10% in some jurisdictions to 100% in others ^[5]. Knowing your state's intended ratio matters. If your assessor says your home is worth $400,000 but every comparable sale in your neighborhood prices similar homes at $350,000, you have a case.

One practical test: divide your assessed value by the sales price of your home (or a recent appraisal). If that fraction is higher than the legally mandated assessment ratio in your jurisdiction, you're likely over-assessed ^[1].

How do you find your property's assessed value?

The fastest route is your county assessor's website. Every county in the U.S. has one, and nearly all now offer a free public search by address, parcel number, or owner name. Search for "[your county] assessor" and you'll usually land on the right page within two clicks.

What you'll find there: the parcel number, the land value, the improvement value, the total assessed value, exemptions already applied, and sometimes the prior year's tax bill. Screenshot or print all of it. Dates matter because assessors use a specific lien date or assessment date (January 1 in most states) to freeze the value used for that year's taxes ^[6].

If your county assessor's site doesn't have a search tool, your second option is the county tax collector or treasurer's site. The assessor sets the value; the treasurer/collector sends the bill. Both offices hold your property's assessed value in their records.

Your third option is calling the assessor's office directly. Under most state open-records laws, property assessment data is public record and the office must give it to you. Many offices will also mail you a property record card on request, which shows the characteristics (square footage, bedroom count, year built, condition grade) that produced your assessed value. That card is the starting point for any appeal.

How do you find your property tax rate (mill rate)?

The tax rate that applies to your parcel depends on which taxing districts overlap your address. A single property might be taxed by the county, the city, the school district, a community college district, a fire district, and a library district all at once. Each sets its own rate.

The combined rate is published every year by the county auditor, controller, or budget office, usually in a document called the tax rate schedule, levy summary, or mill rate table. Search "[your county] [year] tax rate schedule" and you'll almost always find a PDF.

Alternatively, your tax bill states the rate directly, either as a percentage or in mills. If your bill shows a rate of 0.0185 (1.85%), that's the same as 18.5 mills. If it shows 25 mills, convert to a percentage by dividing by 1,000, giving 2.5%.

The Lincoln Institute publishes average effective tax rates (taxes paid divided by home value) by state and metro area, which is useful for sanity-checking whether your rate looks right compared to neighbors ^[5]. Their data shows New Jersey's average effective rate regularly exceeds 2%, while Hawaii's sits near 0.3%, one of the lowest in the country.

For county-specific numbers, see our guides on la county property tax, santa clara property tax, and miami dade property taxes.

What exemptions reduce the amount you actually owe?

Exemptions cut your taxable assessed value before the rate is applied. They're the single biggest legal lever most homeowners have, and a shocking number of eligible people never claim them.

The homestead exemption is the most common. It reduces the taxable value of your primary residence by a fixed dollar amount or percentage. Texas offers a $100,000 homestead exemption from school district taxes as of 2023 ^[3]. Florida exempts the first $25,000 of value from all taxes, plus an additional $25,000 from non-school taxes for homesteaded properties ^[7]. California's basic homeowner's exemption reduces assessed value by $7,000 ^[2].

Other exemptions that often go unclaimed: senior/elderly exemptions (age thresholds vary, commonly 62 or 65), disability exemptions, veteran exemptions, and surviving spouse exemptions. Income thresholds apply in many cases. Some states offer circuit-breaker credits that cap property tax as a percentage of household income.

To find every exemption available to you, go to your county assessor's website or your state's department of revenue site. Search "property tax exemptions" plus your state name. You'll find the full list, the application form, and the deadline. Missing a filing deadline for a homestead exemption typically means you lose it for the entire tax year. You can usually apply for the following year, but you can't go back.

For more on specific local tax structures, the nyc property tax guide covers New York City's layered exemption system in detail.

How do you find out how much you paid in property taxes?

You have three reliable sources.

First, your county tax collector's website. Search for your parcel by address and look for a payment history tab. Most modern county sites show every payment made going back five or more years, with the date, amount, and whether it was paid on time.

Second, your mortgage servicer. If your lender collects property taxes through an escrow account (which is standard for most mortgages with less than 20% down), they track every tax payment they make on your behalf. Log in to your servicer's portal or call them and ask for an escrow account history. They're required to send you an annual escrow analysis statement, which shows the total paid out for taxes during the year ^[8].

Third, IRS Form 1098. If you paid mortgage interest during the year, your lender sends a Form 1098 each January. Box 10 (labeled "Other" on older forms, "Real estate taxes paid" on more recent ones) sometimes reports property taxes, though lenders aren't required to fill it in. Don't rely on this alone.

For your federal tax return, the amount that matters is what was actually paid to the taxing authority during the calendar year, not what was deposited into escrow. The IRS is clear on this: deductibility follows the cash-basis rule for individuals, meaning the tax is deducted in the year the payment reached the government, not the year you made escrow deposits ^[9].

If you pay taxes directly (no escrow), pull your bank statements for the payment dates and amounts, or grab receipts from the county collector's site.

How do you look up a property tax bill online?

Go to your county tax collector, treasurer, or assessor's website. Every county website is different but nearly all share the same search fields: property address, parcel number (APN or PIN), or owner name.

Type in your street address. You'll usually land on a parcel summary page showing the current tax year's bill, the due dates for each installment, the amount due, and whether it's been paid. Most sites also show prior year bills.

If you can't find your county's site, the NACo (National Association of Counties) maintains a county directory at naco.org where you can look up your county government's homepage ^[10]. From there, navigate to the assessor or tax collector. Your state's department of revenue website often lists all county assessor links too.

Some counties use third-party platforms like Tyler Technologies' Munis system or Forte Payment Systems. The look differs but the data is the same. For online payment options once you've found your bill, see our online tax payment for property guide.

For specific metro-area lookups, these guides get local: hennepin county property tax, collin county property tax, contra costa county property tax, and williamson county property tax.

Average effective property tax rates by state: what does normal look like?

Effective property tax rate (taxes paid divided by home value) is the most honest comparison metric because it accounts for both the nominal rate and the assessment ratio. Here's a snapshot from Lincoln Institute of Land Policy data and Tax Foundation analysis ^[5][11]:

State	Avg. Effective Rate	Median Home Value (approx.)	Avg. Annual Tax
New Jersey	2.23%	$430,000	$9,589
Illinois	2.08%	$239,000	$4,971
Connecticut	1.79%	$336,000	$6,014
Texas	1.60%	$300,000	$4,800
New York	1.54%	$370,000	$5,698
California	0.76%	$600,000	$4,560
Florida	0.89%	$350,000	$3,115
Colorado	0.55%	$440,000	$2,420
Hawaii	0.32%	$620,000	$1,984

These are state averages. Your actual county can sit well above or below the state figure. Cook County, Illinois, often runs higher than the Illinois average; rural counties in the same state often run lower. Use this table as a rough sanity check, not a precise benchmark.

If your effective rate is well above your state average, that's a signal worth investigating. It doesn't automatically mean your assessment is wrong, but it's a reason to look carefully at your property record card and compare it to recent sales of similar homes in your area.

How do you calculate property tax yourself before an appeal?

Here's the step-by-step process used by anyone filing a DIY appeal.

Step 1: Pull your property record card from the assessor's office. Note the total assessed value and every characteristic listed (square footage, bedroom/bathroom count, lot size, year built, condition).

Step 2: Write down your exemptions. Your assessment notice or the assessor's site will show which exemptions are already applied. Note the taxable assessed value after exemptions.

Step 3: Find the current year's mill rate for your tax code area. This is on your bill or the county's published rate schedule.

Step 4: Multiply taxable assessed value by the mill rate. If the rate is expressed in mills, divide by 1,000 first. Example: $275,000 taxable value x 0.020 (20 mills) = $5,500.

Step 5: Check the math against your actual bill. They should match within rounding. If they don't, call the assessor's office because there may be a special assessment, a delinquent balance, or an error.

Step 6: Now test whether the assessed value is fair. Divide your assessed value by your home's likely market value (use recent comparable sales from Zillow, Redfin, or the county's own sales database). If that ratio is higher than the state's official assessment ratio, you have a quantifiable argument for appeal ^[1].

If the numbers point toward an over-assessment and you want to file your own appeal, a structured DIY approach avoids the 30-50% contingency fees that professional firms charge. The TaxFightBack appeal kit walks through exactly the evidence you need to build your case, from pulling comparable sales to completing the hearing form.

What if your property tax bill looks wrong?

Start with the simplest explanations. Look at your property record card and confirm that the physical facts match reality. Wrong square footage is common. So are phantom bedrooms, incorrect lot size, or a condition grade that hasn't been updated since the assessor last physically visited your home (which may have been years ago).

If you find a factual error (your county thinks your house is 2,400 sq ft but it's 1,950), call the assessor's office and ask for an informal review. Many factual corrections happen without a formal appeal. Bring your original purchase survey, building permit records, or a floor plan.

If the facts are right but the value is wrong relative to comparable sales, that's an equity or market value appeal. Most counties allow you to file a formal appeal with the local board of review or appraisal review board. Deadlines are strict. Missing them by one day in most jurisdictions means you wait until next year ^[6].

For context on how appeals work in specific high-cost markets, see our san mateo county property tax and detroit property taxes guides.

As a rule, gather at least three comparable sales (homes similar in size, age, and location that sold within the past 12 months) that show lower value per square foot than what your assessment implies. Present those sales at your hearing. The International Association of Assessing Officers (IAAO) states in its Standard on Mass Appraisal that an acceptable median ratio of assessed-to-market value is between 90% and 110% ^[12]. If your ratio exceeds 110%, you have a textbook argument.

How do property taxes work if you pay through an escrow account?

About 80% of mortgaged homeowners pay property taxes through escrow, according to the Consumer Financial Protection Bureau ^[8]. Here's how it works.

Your lender estimates your annual property tax bill, divides it by 12, and adds that amount to your monthly mortgage payment. The lender holds those funds in a restricted account and pays the tax authority directly by the due date. The lender can collect up to two months' worth of cushion on top of the projected annual amount ^[8].

Two things go wrong routinely. First, if your assessment goes up mid-year, the lender may not catch it until the annual escrow analysis, then suddenly raise your monthly payment to cover the shortfall. Second, if your assessment goes down (say, after a successful appeal), you may be owed an escrow refund. The servicer is required to issue a refund within 30 days of the annual analysis if there's a surplus of more than $50 ^[8].

You still own the tax obligation. If your lender misses a payment (rare but it happens), penalties and interest accrue against you, not the lender. Log into the tax collector's site once or twice a year to confirm payments are showing as received.

One more thing. Even with escrow, you might qualify for an exemption that reduces your bill midyear. File the exemption application anyway. The assessor will adjust the bill, the collector will update the balance due, and your lender's next escrow analysis will recalculate your monthly payment downward.

Are there deadlines you need to know?

Yes. Missing the right deadline in property tax can cost you a full year's opportunity.

The three deadlines that matter most:

1. Exemption application deadline. Most states require you to file for a homestead exemption (and other exemptions) before a specific date, often January 1, March 1, or April 1 of the tax year. Texas's homestead exemption application deadline is generally April 30 ^[3]. Florida's is March 1 ^[7]. Filing late usually means you lose the exemption for that year.

2. Appeal filing deadline. After your assessment notice arrives, you typically have 30 to 90 days to file a formal appeal. California's Assessment Appeals deadline for most counties is November 30 for a July 2 roll change, or 60 days from the mailing date of an assessment notice, whichever is later ^[2]. Texas has 30 days from when the appraisal district mails the notice of appraised value ^[3]. New York City's deadline is March 15 for most residential property ^[4].

3. Tax payment due dates. Most states split the bill into two installments. In California, the first installment is due November 1 (delinquent after December 10) and the second is due February 1 (delinquent after April 10) ^[2]. In Texas, the full bill is due January 31 ^[3]. Late payment triggers penalties that often start at 5-10% and compound monthly.

Set calendar reminders. The deadlines are fixed, and assessment authorities don't grant extensions for "I didn't know."

Frequently asked questions

How do I figure out my property tax if I just bought my home?

Look up your county assessor's website and search for your new address. Your assessed value may differ from your purchase price, especially in states like California where a sale triggers a reassessment to purchase price. Multiply the assessed value (minus any exemptions you qualify for) by the local mill rate shown on the county's published tax rate schedule. Your first bill should arrive within the first tax cycle after closing.

How do I find out how much I paid in property taxes last year?

Check your county tax collector's payment history page (search by your address or parcel number). If you pay through escrow, your mortgage servicer's annual escrow analysis statement lists exactly what was paid and when. Your lender's Form 1098 may show property taxes in Box 10, though lenders aren't required to fill that box. The definitive record is the county collector's site.

How do I find my property tax bill online?

Go to your county tax collector's or treasurer's website. Search by property address, parcel number, or owner name. The results show the current bill, due dates, and payment status. If you can't find your county's site, the National Association of Counties directory at naco.org lists every county government homepage.

How do I find out my property tax rate?

Your annual tax bill states the rate directly, either as a percentage or in mills. You can also search your county auditor or controller's website for the current year's tax rate schedule or levy summary, which is a public document. Your county assessor's parcel detail page sometimes shows the tax code area and the combined rate for your specific address.

What does mill rate mean on a property tax bill?

One mill equals $1 of tax per $1,000 of assessed value, or 0.1%. A mill rate of 20 means you pay $20 for every $1,000 of taxable assessed value. To convert mills to a percentage, divide by 1,000. So 20 mills equals 2.0%. Multiply that percentage by your taxable assessed value to get your annual tax bill.

Can I appeal my property tax assessment myself without hiring a firm?

Yes. The formal appeal process is open to all property owners and requires no legal representation. You need to file the correct form with your local board of review or appraisal review board before the deadline, then present comparable sales or a factual error as your evidence. Most hearings are informal. Contingency firms charge 30-50% of your savings; doing it yourself keeps 100%.

How do property taxes work when you have a mortgage?

Your lender typically collects a monthly escrow payment equal to roughly one-twelfth of your estimated annual tax bill, then pays the taxing authority directly by the due date. CFPB rules limit the cushion a servicer can hold to two months' worth of payments. If a surplus over $50 remains after the annual escrow analysis, the servicer must refund it within 30 days.

What is the difference between assessed value and taxable value?

Assessed value is the raw value assigned by the assessor. Taxable value is assessed value after subtracting any exemptions (homestead, senior, disability, etc.). Your tax rate is applied to taxable value, not assessed value. Claiming every exemption you qualify for is usually the lowest-effort way to reduce your tax bill without filing a formal appeal.

How often is property tax reassessed?

It varies by state and county. Some jurisdictions reassess every year; others every two, three, or four years; some only upon a sale or new construction. California reassesses to purchase price on a sale but otherwise caps annual increases at 2% under Proposition 13. Texas appraisal districts appraise annually as of January 1. Check your state's department of revenue site for the local cycle.

Is property tax deductible on my federal income tax return?

Generally yes, as a state and local tax (SALT) deduction, but the Tax Cuts and Jobs Act of 2017 capped the total SALT deduction (including property taxes, state income or sales taxes) at $10,000 per year ($5,000 if married filing separately) through at least 2025. The IRS allows deduction in the year taxes are actually paid to the government, not when deposited into escrow.

What happens if I don't pay my property tax?

Penalties and interest begin accruing immediately after the due date, often at 5-10% of the unpaid amount, with additional monthly charges. After a period that varies by state (commonly one to three years), the county can initiate a tax lien sale or a tax deed proceeding, which can ultimately result in loss of the property. Contact the collector's office early; most offer payment plans for delinquent accounts.

How do I find my parcel number to look up my property tax?

Your parcel number (also called APN, PIN, or tax ID) appears on your deed, your title insurance policy, your mortgage closing documents, and any prior tax bill. If you don't have any of those handy, go to your county assessor's site and search by address. The parcel detail page will show the number. You can then use that number for faster lookups on any county platform.

What if my property tax went up a lot this year?

Check whether your assessed value rose, the tax rate rose, or an exemption was removed. Log into the assessor's site and compare this year's assessment notice to last year's. If the assessed value jumped above comparable sales prices, file an appeal before your jurisdiction's deadline. If an exemption disappeared, contact the assessor's office because it may be a data error that can be corrected without a formal hearing.

How do I know if I'm over-assessed?

Divide your assessed value by your home's probable market value (use recent comparable sales). If that ratio is higher than your state's legally mandated assessment ratio, you're likely over-assessed. The International Association of Assessing Officers considers assessments within 90-110% of market value as acceptable. Above 110% is a measurable basis for appeal. Pull three to five comparable sales within the past 12 months to document the gap.

Sources

1. Lincoln Institute of Land Policy, Significant Features of the Property Tax: Mill rate definition: one mill equals $1 of tax per $1,000 of assessed value; assessment ratio is the ratio of assessed to market value
2. California State Board of Equalization, Property Tax Publication 29: California's Proposition 13 caps annual assessment increases at 2%; basic homeowner's exemption is $7,000; Assessment Appeals deadline for most counties is November 30 or 60 days from mailing
3. Texas Comptroller of Public Accounts, Property Tax Exemptions: Texas assesses at 100% market value; caps annual increases at 10% for homesteaded properties; $100,000 homestead exemption from school taxes (2023); exemption deadline generally April 30; appeal deadline 30 days from mailing of notice
4. Lincoln Institute of Land Policy, 50-State Property Tax Comparison Study: Effective residential assessment ratios range from under 10% to 100% across jurisdictions; New Jersey average effective rate regularly exceeds 2%; Hawaii average effective rate near 0.3%
5. International Association of Assessing Officers (IAAO), Assessment Administration Reference Manual: Assessors use a specific lien date or assessment date to freeze values; most states use January 1; appeal deadlines are strict and missing them by one day forfeits the right to appeal for that year
6. Florida Department of Revenue, Property Tax Exemptions: Florida homestead exemption: first $25,000 from all taxes plus additional $25,000 from non-school taxes; application deadline is March 1
7. Consumer Financial Protection Bureau, Escrow Accounts: About 80% of mortgaged homeowners pay property taxes through escrow; servicers may hold up to two months' cushion; surplus over $50 must be refunded within 30 days of annual escrow analysis
8. IRS Publication 530, Tax Information for Homeowners: Property taxes are deductible in the year actually paid to the government on a cash basis; SALT deduction capped at $10,000 per year under Tax Cuts and Jobs Act of 2017
9. National Association of Counties (NACo), County Directory: NACo maintains a public directory of all U.S. county government homepages
10. Tax Foundation, Property Taxes by State: State average effective property tax rates: New Jersey 2.23%, Illinois 2.08%, Connecticut 1.79%, Texas 1.60%, California 0.76%, Hawaii 0.32%
11. International Association of Assessing Officers, Standard on Mass Appraisal of Real Property: IAAO states that an acceptable median ratio of assessed-to-market value is between 90% and 110%